Plug and receptacle construction



Mmc @g ww 1; Mmmm mgvs@ FLUG mn mamme@ comsaucmom Filed Dec. 22, 195o .2 mmm-Smm' 2 nimm/fr 2,703,830 PLUG AND RECEPTACLE CNSTRUCTHN Christian Miller, Norwalk, Conn., assnor to Edwards Company, Inc., Norwalk, Conn., a corporation of New York Application DecemherZZ, 1950, Serial No. 202,157

22 Claims. (Cl. 20G-51.1)

This application is a continuation-impart of my application Serial No. 63.937, led December 7, 1948, and of my application Serial No. 34,535, filed lune 22, 1948 (which matured into Patent No. 2,503,286 on April 1i, 1950, since reissued on September 4, 1951 as Reissue Patent No. 23,407 on application for reissue Serial No. 202,283, filed December 22, 1950), which are continuations-in-part of my application Serial No. 742,694, filed April 19, 1947 (now abandoned).

This invention relates to a disconnectable wall plug and receptacle construction for use in a hospital signalling system wherein the patient can manually actuate one or more signals and the circuits operating those signals can be restored by the attendant only at the place the signal was initiated.A More specifically it relates to a plug and receptacle arrangement in which the patient operates the device by an actuator such as a pull chain, pull cord, or similar device located at the wall plug instead of by a manually operable switching device distant therefrom and connected thereto by an extension conductorcontaining cable, as disclosed in my copending application Serial No. 34,535, tiled June .22, 1948, which is also a continuation-in-part of my application Serial No. 742,694, led April 19, 1947.

One of the objects of this invention is to provide a practical and dependable plug and receptacle construction of the above-mentioned nature whereby signalling circuits connected to the wall-mounted receptacle may be dependably actuated by a mechanical actuator such as a chain or cord to reach to the patients bed. Another object is to provide such a plug and receptacle construction in which, by such a mechanical actuator, the patient may also actuate one or more supplementary signal circuits at will even after actuation of the other signal circuits connected to the receptacle, leaving the restoration of all of them under the control, at the wallmounted receptacle, of the responding attendant. Another object is to provide a practical and dependable plug construction attachable, mechanically and electrically, to a wall-mounted signalling receptacle, with the plug construction provided with a mechanical actuator of the above-described nature. Another object is to provide a plug construction of the just-mentioned nature provided withreasily controlled and dependable manually actuated signal circuit restoring means whereby the responding attendant can reset the signal circuits at the wall location of the plug and receptacle, the resetting means being thus out of reach of the patient.

Another object is to provide a plug connector assembly having a remote-control mechanical actuator operable by the patient and interchangeably usable with a signal circuit wall-mounted receptacle construction of the type that is usually employed with a patient-controlled push button switch at one end of a flexible cable, at the other end of which is a plug connector that coacts with the receptacle parts. Another object is to provide a plug connector of the just-mentioned nature constructed also to make possible the manual control or actuation of certain signal circuit restoring devices usually associated with such receptacles.

Another object is to provide a simple, compact, and eective plug connector having a dependable mechanical actuator of the above-mentioned type and also provided with a manually controlled device constructed and arranged to eoact with and control the receptacle-carried resetting device and adapted to be brought into coacting i i im@ v relation with the latter upon assembly of the plug con nector to the receptacle.

Another object is, in general, to provide an improved and superior plug connector and receptacle construction for hospital signalling systems in which a remote-control actuator is embodied for signalling by the patient and a signal circuit restoring device is made accessible at the location of the plug connector and receptacle.

Another object of the invention is to provide a plug connector and resettable receptacle construction in which the plug connector is provided with controllable means that are actuatablc, upon assembly of the plug connector to the receptacle, to effect signal circuit actuation of receptacle parts where the latter stand in reset condition when the plug is assembled to the receptacle. Another object is to provide in the plug connector of such a construction a manually-operable resetting actuator to control resetting of actuated signal circuit controlling parts of the receptacle.

Another object of the invention is to provide a mechanical actuator in the wall plug of a plug and receptacle combination that, upon actuation by the patient, closes several circuits, such as light signalling circuits, until reset by the attendant, but closes another circuit, such as a buzzer circuit, only momentarily. Another object is to provide simple and practical mechanism whereby the patient, with such a mechanical actuator, may actuate such another circuit for longer time intervals and also repeatedly.

Further and additional objects will be in part obvious or in part pointed out hereinafter.

The invention consists in the features of construction, combination of elements, and arrangement of parts as will be exemplied in the construction hereinafter described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings which form a part of this specilication Figure 1 is a plan view of a double receptacle shown in a wall mounting plate, with one receptacle shown ready to receive a plug connector and with the other having assembled thereto a plug connector with a mechanical actuator in the form of a pull chain;

Figure 2 is an exploded view, partly in cross-section, of the receptacle;

Figure 3 is a cross-section of the receptacle on the line 3 3 of Figure 1 with certain mounting parts omitted, such as the wall plate;

Figure 4 is a fragmentary cross-sectional View on the line 4 4 of Figure l showing a form of connection of a. receptacle contact linger to the ground or return circuit;

Figure 5 is a view -in perspective of a restoring plunger employed in the receptacle;

Figure 6 is a cross-sectional view of the receptacle as seen along the line 6 6 of Figure 3;

Figure 7 is a cross-sectional view of the receptacle as seen along the line 7 7 of Figure 3;

Figure 8 is a cross-section of the receptacle along the line 8 8 of Figure 3;

Figure 9 is a plan view of a conductive plate element employed in the receptacle;

Figure l0 is a cross-section of the receptacle as seen along the line 3 3 of Figure 1, but with certain parts omitted, including the upper portion of the non-conductive portion of the receptacle, showing certain receptacle parts in reset position and showing in phantom part of the plug connector in a position spaced from the receptacle, as in course of assembly or removal thereof;

Figure 1l is an elevation of the mechanical actuator unit as seen from the right in Figure 1, parts of the receptacle and its mounting being omitted or broken away;

Figure 12 is a transverse sectional view as seen along the line 12-12 of Figure 11;

Figure 13 is a transverse sectional view as seen along the line 13 13 of Figure 11; .p

Figure 14 is a transverse sectional view as seen along the lino lil-14 of Figure 13 and also along line M M CJ gether make up a rotary unit for the mechanical actuator within the plug;

Figure 16 is an end view as seen along the line lr6-'i6 of Figure l;

Figure 17 is a vertical sectional view as seen along the line 17-17 of Figure l5;

Figure 18 is a vertical sectional view as seen `along the line 18-18 of Figure 15; and

Figure 19 is a vertical sectional view of the assemblage of the three parts shown in Figures to 18, showing how together they make up the rotary unit for the mechanical actuator.

Similar reference characters refer to similar parts throughout the several views of the drawings.

In my above copending application, Serial No. 34,535, Patent No. 2,503,286, being now Reissue Patent No. 23,407, I have shown a receptacle construction, with `an associated plug connector for electrically connecting thereto a remotely-positioned push button switch, with the receptacle constructed and arranged to achieve signal actuation upon removal of the plug and provided with a manual device for resetting receptacle parts to restore the signal circuits to unactuated condition, all constnicted and arranged so that re-assembly of the electrical plug connector to the receptacle automatically reconditions or .z resets the parts for signal actuation should a removal of the plug take place. Herein l describe and show in the drawings that same receptacle construction, with a number of differences, however, later herein pointed out; and l note that Figures l to 10 hereof are the same as Figures l, 3 to 10, inclusive, and l2 of that copending application, excepting that in Figure 1 herein I show, assembled to a receptacle, a plug connector with a manual actuator, such as a pull chain, instead of the plug connector with conductor cable leading to a push button switch as in Figure l of the patent. The plug connector herein and the plug connector of the patent. in spite of certain structural and functional differences, are interchangeably applicable to such a receptacle construction and interchangeably usable in a hospital signalling system according as particular circumstances make the use of one more desirable than the other; for example, a patient might or might not be physically able to manipulate a push button switch but can pull a cord or chain. Also, there are circumstances where use of a push button switch directly by the patient might introduce elements of hazard, as, for example, when the patient is under an oxygen tent and a push button switch actuation might be accompanied by danger ous sparking or arcing. Among the dominent aims ot' this invention are to provide a practical and dependable plug structure having a remotely-controlled mechanical actuator and usable interchangeably in a receptacle construction of the above-mentioned type, while making provision for local controls actuated by the answering attendant; to provide such a plug structure in which the patient can at will, through the remote-controlled mechanical actuator, control supplementary signals; to provide a plug structure having such supplemental signal control that will be compact in construction, neat in appearance, and durable; and to provide such a combination plug and receptacle construction in which the remote mechanical control, associated with the plug structure and certain mechanical and electrical devices of the receptacle structure, can reliably coact to achieve conjoint actuation of a group of signal circuits followed by supplemental repeated signal circuit actuation, at will, of other signal circuits. t

Referring to Figure 3, the receptacle comprises two parts, upper part 21 and lower part 33, made of insulating material, as by molding, and shown also in exploded side elevation inv Figure 2, all with other parts assembled thereto. The lower part has at its lower end a relatively heavy mounting portion 33a which is round in cross-section, and at its upper end it has a horizontally extending flange portion 33b which projects laterally and may be rectangular in shape. as shown in Figure 7. These portions 33 and 33b are joined by vertically extending ribs R spaced about the central vertical axis and substantially equi-angularly, as appears from Figures 7 and 8, forming therebetween (Figure 8) slots or grooves 4l which are exposed laterally and are also in the sides of the lower mounting portion 33; at their upper ends they extend through the horizontal flange portion 33b (Figure 7). In the illustrative embodiment the ribs R are six in number, and so also are the intervening slots 4l.

The upper part 2l (Figures 3 and 6) has a laterally projecting flange portion 2lb which is rectangular in shape to mate with the flange part 33b of the lower part 33 against which it rests, and upstanding therefrom (Figure 3) it has generally cylindrical side walls 21 closed over by a top wall 211 in which are provided holes 46 (see Figure l) that are aligned respectively with the slots 4l in the lower part 33D.

The external contour of the side walls 21n matches the contour of the holes 20u (Figure 1) provided in a wall plate 2li, so that when the receptacle is installed in a wall outlet box and the wall or cover plate 20 applied, as by the screw 2Gb, the upper part 21 of the receptacle tits into the plate opening with thel external surfaces of both substantially aligned.

Where there are six slots 4l. in the receptacle, I provide suitable spring Contact lingers in five of them; these are indicated, respectively, by the reference characters 39B, 39h, 39C, 39d, and 39e (Figures l, 2, and 6 to 8). Each is made of a suitably resilient or spring material, like brass or Phosphor bronze, and each may be of identical shape of conformation, as indicated at 39 in Figures 3 and 4, wherein the spring ngers 39C and 39 are shown in vertical section. Each spring linger (Figures 3 and 4) has a lower portion that bottoms in a slot 4l against the lower mounting portion 33 against which it is secured, as by a screw 42. Each extends upwardly along a slot and terminates in a hole 46 of the upper part 2l, just below the face of the latter, where it is provided with a V-bend 44. An intermediate portion of each spring contact linger, just above the mounting portion 33a, is provided with an inwardly extending U-shaped cam bend 4S, for coactions later described.

Preferably, also, each spring finger is backed up by one or more relatively stiff at springs 43 which are preferably held spaced outwardly from the upper portion of the spring finger 39, somewhat as indicated in Figures 3 and 4, by suitably imposed metallic spacer plates, and it is through all of these superimposed parts that the screw 42 extends to hold them assembled. Screw 42 also passes through a plate-like connector part 40 which extends downwardly, where it carries a binding screw 40 by which the conductors 0f the circuits are connected to the spring contact fingers. These various superimposed parts all neatly tit into that portion of the slot 41 that is in the side of the lower mounting portion 33', whereby these parts of each contact finger are neatly aligned and hence the screw 42 need only clamp them against the bottom of the slot.

With five contact fingers it is possible to control four signalling circuits, the line or conductor connected to one of them representing the side of the signalling circuits that is common to all.

The Contact fingers, dile to the U-shaped intermediate bends 15S therein, are normally and inherently biased inwardly toward the central vertical axis of the receptacle, as viewed in Figures l, 3 and 7, and unless otherwise controlled or restrained, they arc thus pressed into conductive contact with a circuit-closing metal contact plate 47 shaped as shown in Figure 9, being externally substantially hexagonal and which is set or recessed fiat wise into the upper face of the ange portion 33h, as is better shown in Figure 7, where the respective corners of the contact plate 47 are shown as resting against the inwardly projecting portions of the ribs R, the upper ends of the ribs R being correspondingly recessed to receive the respective corners of the plate 47 so that its upper face is flush with the upper face of the flange portion 33h. When the upper part 21 is assembled to the lower part. the rib-like parts Rl (Figure 6) inside of the upper receptacle part 2l, and which mate respectively with the ribs R of the lower part 33, overlie the contact plate 47 and hold it in its recessed seat in the lower part 33.

As shown in Figure 7, the side edges of the hexagonal contact plate 47 are presented to or projected into the vertical slots 41 respectively, and the inward bias of the spring Contact fingers brings each of them into good electrical engagement with these side edges; in such case the several signalling circuits would be closed.

Means are provided for moving and holding the spring fingers out of engagement with the contact plate 47, and such means preferably comprises a plunger generally indicated at 3S and shown in perspective in Figure 5; conveniently it s molded out of a suitable insulating material; it has a cylindrical stem 52 which is slidably arenas@ guided in a round hole 33I (Figure 3). .Surrounding the stem 52 is a spring 54 accommodated in a suitable internal recess 53 in the mounting portion 332), and the upper end of spring 54 abut.; against cam part Si that is of substantial axial length and shaped to coact with the U-bends 45 in the contact ngers. Under the bias of spring 54 this cam part 51 is held in uppermost position, as shown in Figures 3 and 4, abutting against the underside of contact plate 47. The plunger 4S has a cylindrical inger piece extension 49 at its upper end that projects through and is slidably guided in a round hole 21I in the top wall 21 of the upper receptacle part 2l. By depressing the finger piece 49, the plunger structure 48 is moved downwardly and the cam part 51 is thus actuated to coact with the U-bends 45 of the spring fingers and press them outwardly and away from the contact plate 47.

Means are provided to hold the plunger structure 48 in depressed position, thus to hold such contact fingers as are actuated by the cam part 51 out of engagement with the circuit-closing contact plate 47. For this purpose there is provided a lug StiL projecting laterally (Figures 3, 6, and 7) from a cylindrical section 50 intermediate of the finger piece 49 and the cam part 51, and contact plate 47 (Figures 9 and 7) is punched out round at 47a and slotted laterally at 47b to accommodate the parts Sil-50EL for easy sliding movement relative thereto. With the hexagonal contact plate 47 seated at its corners (Figure 7) in correspondingly angularly shaped seats as above described, the plate 47 is thereby held against rotational movement, and with the vertically extending lateral lug 50- (Figures 3 and 7) accommodated in the slot 47D throughout the vertical range of movement of the plunger structure 48, the parts 50'L and 47h act like a spline and the plunger structure, though movable vertically, is held against rotational movement, thus to achieve coactions later described.

In one of the slots 41 of the lower part 33, the one at the 9 oclock position in Figures 6, 7, and 8, being the one at the left in Figure 3, is secured a stop or holding member that comprises an elongated part S7 in the form of a strip of dat sheet metal which is of a length to reach upwardly through the upper part 21 of the receptacle, passing freely between two adjacent rib parts Rl in the upper part 21 and through one of the holes 46 in the top wall 21 where, as shown in Figure 3, the member 57 is bent or curved outwardly at a slight angle to provide a handle or operating portion 59 which thus projects outwardly from the end face of the assembled receptacle structure. Within the part 21 the meniber 57 is provided with inwardly projecting spaced ears or lugs 56 (Figures 3 and 6) for coaction with the vertical face of the plunger lug 50* and with the top face thereof.

At its lower end the holding part 57 is mounted so that its upper part, with the lugs 56, is biased radially inwardly toward the plunger structure 48, and this may be achieved by means of a U-shaped strip 57E of good spring metal, one arm of which is secured to the mounting portion 33a by a screw 58 and to the other arm of which the lower end of the stop part 57 is secured, as by a screw 57h.

Accordingly, when the finger piece 49 is depressed and the plunger 48 moves downwardly, the vertical side edge of Athe plunger 50a rides along the stop lugs 56 which spiing or snap radially inwardly to overlie the upper face of the lug 50, thus holding the plunger depressed against the action of spring 54, the cam part 51 pressing and holding spring contact fingers radially outwardly and away from the contact plate 47, all as shown in Figure l0. By actuating the operating portion 59 of the stop part S7 radially outwardly, to the left in Figures 3 and 10, and against the spring bias eiected by the spring mounting part 57a, the lugs 56 are moved out of engagement with the plunger lug 50a and the spring 54 is thus freed to project the plunger structure upwardly into the position shown in Figure 3, a washer 60 of felt, rubber, fiber, or the like, interposed between the top wall 21c and the part 50 of the plunger, acting to bring the plunger structure 48 to a halt with a nice cushioning action.

With the above described construction, many practical advantages are achieved. Insertion of a plug with contact prongs that enter the holes 46 to which the contact springs 39B, 39h, etc., are presented, eects interengagement between the prongs and the contact springs, tlius pressing the latter outwardly away from the conductive plate 47 and thus extending the-circuits of the contact springs through the plug prongs and to a suitable push button switch at the end of the conductors connected to the plug prongs. Should the plug be intentionally or accidentally removed from the receptacle 2li- 33, the contact springs of the latter move into engagement with the conductive plate 47 and thus the severalsignalling circuits are closed and the signalling device is actuated. The responding attendant can then restore the plug, but if the removal of the latter is intentional, the attendant deactivates the signalling circuits by depressing the linger piece part 49 of the plunger 48 (see Figure 3) so that the cam part 5l can open the signalling circuits by pressing contact springs away from the conductive plate 47. Such depression effects an automatic locking of the plunger 48 in depressed position because the lugs 56 on the latch part 57 move radially inwardly over the plunger lug 50 and hold the latter in downward position, as shown in Figure lO. That inward movement of the latch part 57 carries the operator member 59 at the top of the receptacle to a radially inward position whereupon the plunger may be unlocked at any time by manually pressing the operator 59 radially outwardly or, as disclosed in my above-mentioned patent, such unlocking movement may be effected by the plug itself during its movement of assembly to the receptacle, the plug having a cam in its under-face to cam the part 59 to releasing position and having also a suitable recess in its under-face to accommodate the finger piece 49 as it moves upwardly when the plunger is released.

The receptacle structure thus far described is substantially that of my above-mentioned Patent No. 2,503,286, being now Reissue Patent No. 23,407. In Figures 1 and 11-19 herein I have shown a structure by which the same signal circuits may be controlled from the saine type of receptacle structure by a remotely-controlled mechanical actuator, desirably employed in place of the just-described plug and cable and push button switch unit where the latter cannot be or is not employed.

In Figures 1 and 11 this device, constructed as a separate unitary unit, is generally indicated by the reference character 22, and it comprises a housing 24 attachable to the wall-mounted receptacle structure and having ex- .tending therefrom a mechanical actuator, illustratively in the form of a tension member, conveniently comprising a so-called ball chain 23 which may be of any desired length or which may be extended by a cord or the like to be within reach of the patient. Preferably there is provided in a wall of the housing 24 a bell-shaped metal guide 27 through which the tension member 23 extends and which facilitates pulling it from any direction and still transmit the desired actuating force to the interior of the housing 24. Preferably this bell guide 27 is mounted in the side wall 70 of the housing, which conveniently may be cylindrical and has an upper closing wall 7l)a from the top of which projects a depressible button 25 arranged to have certain coactions with the plunger structure 48 scribed. The actuator 23 is in turn arranged to eEect certain controls of the lever or lock member 57 and certain controls of one or more circuits that are extended into the plug housing by suitable lug contacts. For purposes of illustration, l have shownthe structure as eniploying two plug contacts 26 and 28 for thereby extending a signal circuit into the plug structure 22 for such additional control.

Referring rst to Figures 13 and 14, a suitable thickened n portion of the side wall 70 of housing 24 has suitable recesses 70b to receive the horizontal bent ends 7l, 7l of the two contact prongs 26 and 28, being secured by screws 72, 72 threaded into the casing side wall or into threaded metallic inserts (not shown) molded therein. Contact prongs 26, 28, shaped with suitable V-bends (Figure 4) to interengage below the V-bends 44 of the receptacle prong contacts, are spaced -and positioned to enter two holes 46 of the receptacle, to engage the contact springs therein and of the latter one is to be the contact spring connected to the common or return conductor of the several signalling circuits and the other is a contact spring leading to the other side of the signalling device that it is desired to control by the of the receptacle, as is later demechanical actuator; illustratively, that is audible signalling device, such as a buzzer. Accordingly, in the illustrative embodiment, plug prong 2% is to engage receptacle contact linger 39C which is connected to the common or return line and which, as is later described, is constructed to have certain other coactions with the conductive plate 47, and plug prong 26 is to engage receptacle contact spring 39h. In Figures 12, 13, and i4 the plug prongs 26, 28 are shown so spaced about the axis of the unit 22 relative to the bell guide 27 and pull chain 23 that, when the structure is assembled to the receptacle of Figure 1, the plug prongs engage tbc just-described receptacle contacts and the pull chain 23 extends ot to the right, as seen in Figure l where the unit is shown assembled to the right-hand one of the two wall-mounted receptacles.

From contact prongs 26, 2S the circuit is extended inside the plug housing 24 by two elongated spring contacts 73 and 74, made of strip sheet metal, such as brass or Phosphor bronze, having good spring characteristics and bent into the respective shape substantially as shown in Figure 13, each having a tab-like extension, as shown at 75 in Figure 14, for the spring contact '73 which underlies the bent portions 7l of the plug prongs 26, 28 so that they are secured in place by the same screws 72, 72 that hold the contact prongs 26, 28 assembled to the housing 24. These details are clearly in Figures 13 and 14.

The free ends of contact springs 73, 74 are bent to be divergent to form a funnel-shaped entry therebetween for a cylindrical conductive stud 76 (Figures 13, 17, and 19) which is mounted, as a later described, for rotary movement about the axis of the cylindrical housing 24 (clockwise in Figure 13) to enter into the funnelshaped ends and thereafter maintain engagement with both Contact springs to thereby electrically bridge them and close the circuit. Suitable lengths of the spring contacts 73, 74 are bent into arcs (Figure 13) the centers of which are coincident with the axis about which the rotary movement of the stud 76 takes place, thereby also to gain the advantage of a rubbing and cleaning action als the circuit-closing stud 76 moves along in between 1 em.

As shown in Figure 14, contact spring 73 and 74 are above the plane of the lower edge of housing 24, leaving a substantial space between the plane of their upper edges and the under-face of top wall "la of housing 24. In the latter is secured a mounting bushing 77, preferably of metal, provided with a knurled cylindrical face for 'l interlocking and secure engagement with the walls of a hole in the top wall 70a of housing 24, an external flange or lip limiting the entry of the bushing inwardly of the housing.

Bushing 77 is stepped, as shown in Figure 14, and has an elongated cylindrical bearing portion 78 onto which is sleeved and rotatably supported the hub element 79, conveniently in the form of an eyelet, of a rotary structure generally indicated by the reference character (Figures 13. 14. and 19) and conveniently comprising three parts 81. 82. and 83 respectively shaped, as is better indicated in Figures -19, each of them being provided with a round hole 84 through which the eyelet 79 passes, the eyelet aligning all three parts in coaxial relationship, and when turned over at its respective ends (Figures 14 and 19), securing them together to function as a single entity.

Parts 81 and 83 are in the form of sheet-metal stampings, and the intermediate part 82 is a disc-like member of non-conductive material such as fiber or molded plastic. The non-conductive part 82 carries the circuitclosing or bridging stud 76 which is seated in a suitable hole 8S (Figure 17) and extends through a larger hole 86 in the upper metal part 33 (Figure 19) so that stud 76 is not in electrical contact with the part S3. The stud 76 is thus insulatingly supported for controlled movement relative to the contact springs 73, 74.

Part A81 (Figures 15, 16. and 19) has an arcuate portion 87 of substantially the same radius as the intermediate member S2, merging into an arcuate peripheral portion 88 of greater radius. Part 121 also has an extension 90 from one edge of which are bent upwardly two lugs shaped, as is better shown in Figure 19, to provide between them a slot somewhat shaped like a keyhole into which the thinner part or link of the ball chain 23 or other tension member may be snapped or interengaged. Slot formed by lugs is positioned so that the pull chain 23 is held thereby in a plane which coincides substantially with the central plane of intermediate part 82 which can thus function as a pulley against which the pull chain 23 can rest, as indicated in Figures 13 and 14, the arcuate portion 87 functioning as one tiange of the pulley. The innermost lug 90 enters a slot 91. of the intermediate part 82 to prevent relative rotary motion between parts 31 and 82. Opposite lugs 90 there is bent downwardly (Figure 19), out of the part 89, a hook-shaped lug 92 with which a springarm, later described, is to be engaged.

The part S3 also has successive arcuate or peripheral portions 93 and 94 of radii substantially like those of the portions 87 and 38 of part 3l, and also a hole 86 opposite the end of contact stud 76 to prevent electrical Contact therewith. From the peripheral portion 93 (Figure 15) there is bent an ear or lug 95 which, upon assembly of the three parts 81, 82, and 83, enters into a peripheral recess 96 of the intermediate part 32 and recess 97 of part 31 and prevents relative rotary motion therebetween. The arcuate portion 94 thus forms the other ange of the pulley-like structure for maintaining constancy of length of radius or lever arm through which the pull chain 23 exerts its rotary effect upon the builtup rotary structure 80 throughout its range of rotary movement.

As is better shown in Figures 15, 18, and 19, in line with the extension '69 of the part Sl, the part 83 also has an extension 98 whence it is bent upwardly in Figure 15 (downwardly as viewed in Figure 14) and then horizontally (Figures 18 and 19) to terminate in a vertically extending flange 99 which can have a curvature (Figure 15) along an arc whose center is not coincident with the axis of rotary movement of the structure 80 or it can be straight and at a suitable angle to any radius drawn from the axis of rotation to it in order to give it, when it engages the projecting lever part 57 of the receptacle structure, a suitable resolution of the force of its rotary movement into a radial outward component to move the lever 57 radially outwardly to disengage the stop member 56 from the stem member 48.

Before assembling the built-up rotary structure 80 to the depending bushing 77, as in Figure 14, a helical spring 100 is slipped onto the larger-diameter stepped portion of the bushing and has one end 101 secured in a slot 102 (Figure 13) provided in housing 24 for that purpose. As the assembled rotary unit 80 of Figure 19 is now assembled onto the stud-like bushing 77, in a position inverted from that shown in Figure 19, the hook-shaped lug 92 is brought into engagement with the other arm 103 (Figure 13) of the spring 100, the tension of the spring being such as to rotate and bias the rotary structure 80 in counter-clockwise direction as seen in Figure 13. A portion of the side wall of housing 24 is suitably shaped to form a stop (to the left of prong 26 in Figure 13) for the end edges of the cam part 99 and part 83, thus to determine the normal or at-rest position of the rotary structure S0. The latter is held assembled to the bushing 77 by a split spring ring 104u (Figure 14) that is snapped into a suitable peripheral groove formed in the end portion of the bushing so that the split ring bears against the lower turned-over part of the hub-like eyelet 79 which thus also forms a bearing bushing for the rotary structure.

That at-rest position of the parts may also be in part determined by a stop member such as a ball link 104 of increased diameter on pull chain 23 to coact with bell guide 27 (see Figure 13) and limit the amount of pull chain 23 which the rotary action of the spring on rotary member 80 can draw into the plug housing and also aid in maintaining it in proper coaction with the abovedescribed pulley-like parts.

n the at-rest position of the parts, cam member 99 (Figure 12) is spaced a substantial arcuate distance from inwardly projecting lever end 59, illustratively about 90 degrees. and by reference to Figure 13, contact stud 76 is spaced from contact springs 73 and 74 by just about the same amount.

With the plug unit 22 assembled to the receptacle structure as above described and preferably secured thereto, as is later described, and with lever 57 swung radially inwardly so that stop member 56 holds plunger stem 413 and cam 51 in lowermost position, whereby spring orintacts 39 are in turn held out of engagement with plate 47 and the circuits are all open, the patient can pull pull chain 23, thus rotating rotary structure d@ the bias of spring lili?, the rotation taking place clockwise in Figure 13 to move cam 99 (countenciocltwise in ure l2) into camming engagement with projecting lever end 59 to cause stop member 56 to release stem ttl and permit upward movement of frusto-conical section l, thereby letting spring contacts 39 move radially inwardly to engage plate Ai7 and thus actuate all of the signals in the circuits of such spring contacts 39 as are in the circuits affected by plate l? and spring contacts 39 engaging it.

The upward movement of stem i8 that takes place when frusta-conical section 5l moves upwardly as above described, projects the button upwardly and out of the upper part of housing 24 (Figure 14); button 25 is preferably cylindrical, made of a non-conductive material such as molded plastic, and is slidably accommodated in a cylindrical recess of bushing 77, the recess being of a depth to just accommodate button 25 when it is in its lowermost position so that it does not materially project from housing 24 and hence, when entered into the recess, is not in a position to be manually actuated. Button 25 is secured, as by threading, to the upper end of a metal stern 105 that is slidably guided in a bore in bushing 77'. Lower end of the bushing 77 is counterbored, as indicated in Figure 14, to accommodate a helical spring 196 whose lower end abuts against the head 105a of the stem M5, spring 106 biasing the stem M5 and the button 25 downwardly. These parts are coaxial with the stem 49 of plunger 48, and when mechanical actuator unit 22 is assembled to the receptacle structure, the spring llllti insures that the lower end of stem MP5 is always held against the upper end of the receptacle stem 49.

lf the latter is in depressed position, button 25 is in its lowermost position and accommodated in the recess in housing 24. When the pull chain 23 operates rotary structure 80 as above described to move the stop member 56 to the left, the upward movement of plunger d@ effects a like upward movement of the stem i195 and button 25 against the action of spring 106, thus putting button 25 in projected position for subsequent manual actuation. The answering attendant thereupon simply presses button 25 downwardly, thereby to restore plunger 48 vto its depressed position in which stop member 5o comes into action to hold the parts in depressed position and thereby inactivate the signals by pushing and holding spring contacts 39 away from plate 47. Button 25 remains in the recess in housing Ztlfunder the action of spring 106 which causes stem 195 always to follow the movements of plunger 458. The mechanism is ready for a subsequent actuation by the patient.

Where, however, the mechanical actuator unit 22 includes an auxiliary switch, such as the parts 73-7476 above described, and plug prongs such as the two contact prongs 26, 28, provision is made to insure that the signalling circuits that are closed by receptacle spring contacts engaging the conductive plate 47 when the rotary cam 99 actuates release lever 57-59, are so closed even though the plug contact prongs 2d, 28 are in engagement with two of the receptacle spring contacts, and so that the auxiliary switch 73-7476 in the plug unit 22 will function without being interfered with by the closure of the other signalling circuits at the circuit-closing plate 47. An illustrative and advantageous arrangement for these purposes is shown in Figure 4, where the receptacle spring finger 39, connected to the ground or return line as above noted and with which plug prong 2S engages, is shown in a preferred mechanical and electrical inter-relationship with other parts of the receptacle structure. As there shown, spring contact 39C, preferably constructed and shaped just as are the others, namely, 39a, 39h, etc., also has a U-shaped intermediate bend 45 which, as in the other contact springs, forms a cam part for coaction with the frusto-conical side face of the plunger cam 511 (Figures 3 and 5); Contact spring 39h, with which plug prong 26 engages, is of similar shape (Figure 3). With the plug unit 22 assembled to the receptacle, however, the plug prongs 26 and 28 hold their respective receptacle spring contacts 39h and 39c bent or stressed radially outwardly away fromvand out of contact with the conductive plate 47, thus extending the illustrative buzzer circuit to the contact springs 73, 7&2- in the plug unit 22 for individual control thereof by the circuit-closing stud 76 that is actuated in response to pull on the pull chain 23. With the common or return line connected to spring contact 39C (Figure 4), an auxiliary spring contact 39f underlies lthe contact linger 39C extending upwardly therealong and about the U-shaped bend i5 therein to a point adjacent the conductive plate i7 which it engages along its side edge and, as shown in Figure 4, engages also over the upper edge of the plate 97 in that it is bent inwardly over the plate. Auxiliary spring contact 39f is biased radially inwardly to maintain contact and electrical connection with the plate i7 as just described, and accordingly, ii the plug unit 22 has an auxiliary switch and plug prongs, that prong thereof that engages the common or ground-connected spring linger 39C, forces and holds the latter radially outwardly away from the plate 47, but electrical connection with the plate 47 is maintained through the auxiliary contact spring 39I which is biased inwardly and does not follow the contact spring 39C in its radial outward movement.

Accordingly, interconnecting plate 47 yremains connected to the common or return line so that the other signalling circuits can be controlled by engaging or disA engaging their respective contact fingers relative to the conductive plate 47.

The truste-conical cam part 5l on the plunger 48 (Figure 5) is given a flat or straight section 51a where it is juxtaposed to the interlitted U-bends of the auxiliary spring 39f of the spring nger 39 (see Figure 4), for neither of these contact springs need be actuated in response to depression of the plunger 46 and, accordingly, auxiliary contact spring 39 can always remain in electrical engagement with the conductive plate 47.

With the plunger d8 depressed and the locking elements 56 holding it in lowermost position, receptacle springs 39a, 39d, and 39e are held out of contact with the contact plate 57, by the cam 5l, and the corresponding signal circuits are open; the plug prongs 26 and 28 are in engagement with receptacle spring lingers 39b and 39, respectively, and hold the latter outwardly away from the contact plate 037, and with spring contact 39C being in the common side of the signalling circuits, the auxiliary or buzzer circuit is thus extended to the spring contacts 73, 7d in the plug unit 22. Contact plate 47, however, remains connected to the common side by way of auxiliary spring contact 39f which, even though the plunger 48 is depressed, is not disengaged from the plate 57 because ofthe straight section 5l of the cam. Circuit-closing stud 76 (Figure 13) stands disengaged from the arcuate contact springs 73, 7d, and the auxiliary or buzzer circuit is open. The cam 99 of the rotary structure dit is in an at-rest position just about between the holes 46 in the'receptacle below which contact lingers 39b and 39a (Figures 12 and 1) termmate.

Accordingly, when the patient pulls the string or pull chain 23 to rotate the rotary structure 89 in clockwise direction in Figure 13 and in counter-clockwise direction in Figures 12 and l, the eccentric cam 99 sweeps past and over the hole 46 below which is contact spring 39a, and stud 7d swings toward the funnel-shaped mouth of the Contact springs 73, 74; just about when the stud 76 engages the springs' 73, '74%, cam 99 engages the upstanding operator part 59 of the release lever 57; the former closes the buzzer circuit and keeps it closed during continued rotary movement, the latter being eliective to cause the eccentric cam 99 to resolve its rotary movement into a radial outward force against the operator 59 to move the latter radially outward to release the plunger 48 from its depressed position, the frusto-conical portions of the cam 5l, as a result, permitting the contact lingers 39a, 39d, and 390 to move inwardly into contact with plate 47 which is connected through auxiliary contact spring 391' to the common side of these signalling circuits and, accordingly, the signalling circuits of contact fingers 39a, 39d, and 39" are actuated and remain actuated.

Release of the pull chain 23 rotates the rotary structure il@ in reverse direction under the action of spring ltlll, cam 99 returning to its at-rest position shown in Figure i9 and in so doing by-passing the operator part 59 which, by engagement of the lugs 56 With the vertical end face of the plug lug 59B, is held in radially outermost position and out of the path of return movement of the cam 99; contact stud 7e disengages itself from contact springs 73,

74 and, while the other circuits remain actuated, the buzzer circuit by this disengagement is interrupted, lf the patient does not get an immediate response, the patient can again pull the chain 23 to close the buzzer circuit, and this he can do as many times as the emergency might require. Such repeat actuation of the auxiliary signalling circuit does not affect the signalling circuits acn tivated by engagement of the contact fingers 39, 39d, and 39e with the grounded contact plate 47.

When the attendant responds, the attendant simply pushes the button 25 of the plug structure 22 inwardly (down, in Figures 11 and 14), thus, through the stem 105, depressing the plunger 48 to cam contact fingers 398, 39d, and 39e away from the contact plate 47, thus interrupting the corresponding signalling circuits, lock arm 57 moving radially inward to catch and hold the plunger in ydepressed position at the parts 56 and 50a (as in Figure and thus also restoring the operator member 59 to a position where it stands in the path of subsequent rotary movement of the cam 99 in the plug structure 22.

With the plug structure 22 of Figures 1 and 14, it is preferred not to place entire reliance upon the prongs, such as prongs 26 and 28, to hold the plug assembly to the receptacle, and in case the auxiliary switch and coacting plug prongs are omitted, it is preferred to provide additional or other securing means. Referring lrst to Figure l, I provide the front face 21cr of the receptacle structure with a suitable number, illustratively two, threaded holes 107 and 108 formed in the plastic or provided therein by metal inserts (not shown) conveniently diametrically opposed, and in the plug housing of Figures 1 and ll-l4 I provide two diametrically opposed screws 109 and 110 (Figures 1, l2, and 13) whose lower threaded ends (see Figure I4) extend below the lower edge of the plug housing 24 for threaded engagement with the threaded receptacle holes 107 and 108, respectively, thus to detachably secure the plug structure to the receptacle structure. These two screws are preferably embodied in the plug housing 24 so that they cannot easily be removed therefrom and form a part thereof, as is better shown in Figure 14 with respect to the screw 110, the other being similarly arranged and constructed. Thus, in a thickened part of side wall 70 of plug housing 24 I provide a bore 111 to snugly receive the shank of the screw; the bore is counterbored at its upper end to accommodate the head of the screw and also at its lower end to accommodate the lthreaded part of screw 110. About the latter is thrust,

in assembly, a split spring wire ring 112 which locks itself to the threads and, being of larger diameter than the bore 111, prevents the screw 110 from sliding upwardly out of the bore.

The two screws also serve as locators for purposes of assembling the plug structure 22 to the receptacle structure, thereby to insure that the plug prongs are entered into the proper openings in the receptacle structure and thus also to insure that the cam part 99 (Figures l2 and 13) is positioned for proper coaction with the lever end 59. The screws when driven home also supplement dependably any anchorage provided by the engagement of the plug prongs with the receptacle structure and maintain the assemblage against the stresses which the external actuator member 23 may impose upon it. On the other hand, the screws permit ready detachment of the plug structure 22 without loss of the screws, in case it is desired to convert the signalling station to push-button switch control, as by the plug and cable structure earlier mentioned.

It will thus be seen that there has been provided in this invention a hospital signalling plug and receptacle construction in which the various objects heretofore set forth and many thoroughly practical advantages are successfully achieved. The receptacle structure will be seen to function as intended where it is desired to use with it a plug and cord and push-button switch unit, where the patient is to operate the push button, and that where it is not desired or feasible to use such a push-button unit, the receptacle structure can have assembled to it the abovedescribed mechanical actuator which is remotely controlled by the patient, as by a pull chain, string, or like extension, with or without supplementary signal circuit control. This latter arrangement is particularly advantageous where the patient is placed under an oxygen tent.

Furthermore, the construction is compact and of reliable action. The receptacle structure, comprising illustratively the two upper and lower portions 21 and 33, is easily and dependably assembled, the two portions being secured together at diagonally opposite corners of the flange parts 21b and 33a'J (see Figures 6, 7, and 3), these flange parts being provided with suitable holes 37 and 38, respectively, for the reception of screws or bolts B to secure the two parts together. At the other diagonally opposite corners the flange part 21b is provided with frusto-conical projections 34, 34 (Figure 6), one of them being of larger diameter than the other, for reception into correspondingly differently sized recesses 36, 36 in the flange part 33b (Figure 7), so that the upper and lower portions 21 and 33 can be assembled and secured together only in vone relationship to thereby insure proper relationship between them and the other parts. Desir- 'ably, the hole 46 (see Figure l) through which the release lever extension 59 (Figure 3) projects, is smaller than the rest of the holes in the top wall 21=, thus to coact with the extension 59 in preventing a plug prong entering that hole and thus to insure that the plug is always properly assembled to the receptacle.

As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

l. In a hospital signalling system, a plug and receptacle construction for controlling a plurality of signalling circuits, the receptacle having a plurality of contacts for connection to said plurality of signalling circuits and having an electrically conductive plate with which said contacts may coact for closing said signalling circuits, said plug having therein a pull chain operated mechanism comprising rotary means operated in one direction in response to actuation of the chain of the pull chain operated mechanism and a spring for operating it in opposite direction upon release of the chain of said mechanism, means coacting with the contacts connected to one of said signalling circuits and responsive to operation of said rotary means first in said one direction and then in said opposite direction to effect respectively circuit-closing action and circuit-opening action, means responsive to operation of said rotary means in said one direction for effecting and maintaining circuit-closing contact between said conductive plate and the contacts connected to the others of said signalling circuits, independent means in said receptacle with an actuator therefor in said plug for opening said other circuits whereby said circuits are conditioned for further signalling, and means in said receptacle causing the contacts therein and said electrically conductive plate to contact for circuit-closing in response to plug removal from said receptacle.

2. In a hospital signalling system, a plug and receptacle construction including means for controlling a plurality of signalling circuits and a supplementary signalling circuit by which said supplementary signalling circuit is closed by rotation in one direction of a pull chain operated mechanism contained in said plug and opened by the release of said mechanism by spring actuated means causing its rotation in the opposite direction and all said first signalling circuits are closed by rotation of said pull chain operated mechanism causing contacts associated with said first signalling circuits to contact an electrically conductive plate in said receptacle but are not opened by rotation of said mechanism in the opposite direction, a centrally located plunger in said receptacle with an actuator therefor in said plug for opening said first signalling circuits whereby said circuits are conditioned for further signalling, and the contacts associated with said supplementary signalling circuit in said receptacle being springbiased causing said contacts to contact said electrically conductive plate when said plug is removed from said receptacle whereby said circuits are closed.

3. In a hospital signalling system, a plug and receptacle construction including means for controlling a plurality of signalling circuits and a supplementary signalling circuit by which said supplementary signalling circuit is closed by rotation in one direction of a pull chain operated mechanism contained in said plug and opened by the release of said mechanism by spring actuated means causing its rotation in the opposite direction and all said first signalling circuits are closed by rotation of said pull chain operated mechanism causing contacts associated aseasso with said first signalling circuits to contact an electricaily conductive plate in said receptacle but are not opened by rotation of said mechanism in opposite direction, a centrally located plunger in said receptacle with an actuator therefor in said plug for opening said iirst signalling circuits whereby said circuits are conditioned for further signalling, the contacts associated with said supplementary signalling circuit in said receptacle being spring-biased causing said contacts to contact said electrically conductive plate when said plug is removed from said receptacle whereby said circuits are closed, and means associated with said plunger for locking it in opencircuit position.

4. In a hospital signalling system, a plug and receptacle construction including means for controlling a plurality Iof signalling circuits and a supplementary signalling circuit by which said supplementary signalling circuit is closed by rotation in one direction of a pull chain operated mechanism in said plug and opened by the release of said mechanism by spring actuated means causing its rotation in theopposite direction and all of said first signalling circuits are closed by rotation of said pull chain operated mechanism causing contacts associated with said rst signalling circuits and an electrically conductive plate in said receptacle to contact for circuit-closing action but are not opened by rotation of said mechanism in the opposite direction, independent means in said receptacle with an actuator therefor in said plug for opening said first signalling circuits whereby said circuits arev con ditioned for further signalling, means in said receptacle causing the contacts therein and said electrically conductive plate to contact when said plug is removed from said receptacle whereby said circuits are closed, and manual means for moving and holding said contacts out of contact with said plate, saidlast-mentioned means including a manually operated plunger in said receptacle having a frusto-conical section cooperatingwith said contacts in said receptacle and means for locking said plunger in a position where it prevents said contacts from contacting said plate.

5. In a hospital signalling system, a plug and receptacle construction including means for controlling a plurality of signalling circuits by which one of said circuits is closed by a pull chain operated mechanism contained in said plug comprising a rotatable element having thereon a bridging stud adapted upon rotation to contact two arcuate shaped contact prongs connected to two contact tingers extending outside of said plug and into said receptacle and in contact therein with corresponding contact lingers, cam actuating means on said rotatable element acting upon rotation of said element to close other circuits in said receptacle by permitting the radially inward motion of other contact ngers therein to contact a conductive metallic plate, spring means to reverse the rotation of said rotat able element when said pull chain is released and thereby to withdraw said bridging stud from said contact prongs and open the circuit previously closed thereby, whereby the circuit previously closed by said bridging stud remains open but all other of said circuits remain closed, and an independent means in said receptacle with an actuator therefor in said plug for opening said other circuits whereby said circuits are conditioned for further signalling.

` 6. In a hospital signalling system comprising al plurality of signalling circuits, a plug and receptacle construction in which a plurality of signalling circuits are connected to contact fingers in said receptacle and are closed by contacting of said iingers with an axially centrally located conductive metallic plate and in which one signalling circuit is closed by the insertion between and contact with of a metallic bridging stud and two contact elements in said plug connected to contact fingers in said plug which extend beyond said plug and are adapted to contact corresponding contact fingers in said receptacle when said plug is inserted in said receptacle, means for causing said insertion of said bridging stud between said two contact elements comprising a rotatable element in said plug upon which said bridging stud is mounted which is manually operated by a pull chain, means for opening said circuit comprising a` coil spring tending to rotate said rotatable element in a direction opposite to that in which it is rotated by said pull chain whereby upon release of said pull chain said rotatable element is rotated in said direction and said bridging.

stud is withdrawn from said contact elements, and means for opening the circuits closed through said conductive metallic plate in said receptacle including a plunger ele- .plunger is in an extended position said contact'ngers are in contact with said conductive metallic plate, means for lockin said operating plunger in its depressed position, said ocking means being arranged to be released by a cam member mounted on said rotatable element in said plug when said rotatable element is operated by said pull chain but to be unaffected by said cam member when said rotatable element is rotated in the opposite direction, and push button means in said plug having a shaft in contact with the end of said operating plunger and adapted to follow the motion of said operating plunger whereby when said operating plunger is in its extended position said push button extends beyond said plug and said operating plunger may be returned to its depressed position by pressing said push button.

7; A signalling plug and receptacle construction comprising a plug body having plug contacts and a receptacle body having a plurality of recesses for the reception of plug contacts, a plurality of receptacle contacts carried by said receptacle body and respectively exposed in said recesses for engagement respectively by such plug contacts as are entered thereinto, one of said receptacle.

contacts having connected thereto the common side of a plurality of signalling circuits of which the remaining sides are connectible to others of said receptacle contacts, circuitcontrolling means associated with said receptacle body and including conductive means adapted to coact to control the opening and closing of at least one of said circuits and havingtwo control members therefor movably mounted with respect to said receptacle body and respectively adapted to control circuit closing and circuit opening actuation of said circuit-controlling means, means associated with said plug body and including switching means carried thereby having connection with that plug contact that engages that receptacle contact that is connected to the common side andl having connection also with a plug contact that engages a receptacle contact in a circuit other than the circuit or circuits controlled by said conductive means, control means carried by said plug body for controlling said two control members and said switch means, said control means comprising a movable cam for actuating that one of said two control members that causes circuit closing actuation of said circuit-controlling means, means operable from the exterior of said plug body for effecting movement of said cam and for actuating said switching means, said receptacle body having associated with it means responsive to the actuation by said cam of said control member for holding the latter out of coacting relation to said cam whereby subsequent re-actuation of said cam effects reactuation of said switching means and an actuator for the other of said two control members and having a manual operator externally exposed from said plug body whereby said circuit-controlling means is actuated in crcuit opening direction.

8. A signalling plug and receptacle construction comprising a plug body, a receptacle body having a recessed end face for entry thereinto of plug contacts of a plug and having contact elements therein engageable by the plug contacts for thereby extending signalling circuits, said receptacle body having a movable spring-biased member projectable out of said end face and said plug body having a hollow space in its bottom end into which a portion of said movable member may enter, said plug body having a exible pull member extending through a wall thereof from its exterior and having movably mounted therein an actuating means responsive to actuation of said exible pull member, means responsive to disengagement of said plug contacts from said receptacle contact elements for etecting closure of at least certai'n of said signalling circuits and means responsive to inward movement of said movable member from projected position for effecting opening of the signalling circuits that are closed in response to disengagement of the plug jection, and threaded means for detachably securing said plug body to said receptacle body to locate and maintain the path of movement of said plug-carried actuating means in coacting relation to said receptacle-carried movable control member whereby the latter is actuated in releasing direction in response to external pull on said pull member.

9. A signalling plug and receptacle construction comprising a plug body, a receptacle body having a recessed end face for entry thereinto of plug contacts of a plug and having contact elements therein engageable by the plug contacts for thereby extending signalling circuits` said receptacle body having a movable spring-biased memn ber projectable out of said end face and said plug body having a hollow space in its bottom end into which a portion of said movable member may enter, means re sponsive to disengagement of said plug contacts from. said receptacle contact elements for effecting closure of at least certain of said signalling circuits and means responsive to inward movement of said movable member from projected position for effecting opening of the signalling circuits that are closed in response to disengagement of the plug contacts from the receptacle contact elements, a movable control member carried by said receptacle body and accessible at its said end face and having means operating to hold said spring-biased member in inward position against the bias of its spring and operating when moved to release said spring-biased member for outward projection, said plug body having an operating element having means mounting it for movement relative to the plug body and along a path to engage said movable member and effect movement there of, said plug body having extending therefrom a springretracted tension element, and means responsive to a stroke of movement of said tension element for operating said movable element to actuate said spring-biased control member.

l0. A signalling plug and receptacle construction comprising a plug body, a receptacle body having a recessed end face for entry thereinto of plug contacts of a plug and having contact elements therein engageable by the plug contacts for thereby extending signalling circuits. said receptacle body having a movable spring-biased member projectable out of said end face and said plug body having a hollow space in its bottom end into which a portion of said movable member may enter, means responsive to disengagement of said plug contacts from said receptacle contacts elements for effecting closure of at least certain of said signalling circuits and means responsive to inward movement of said movable member from projected position for effecting opening of the signalling circuits that are closed in response to disengagement of the plug contacts from the receptacle contact elements, a movable control member carried by said receptacle body and accessible at its said end face and having means operating to hold said spring-biased member in inward position against the bias of its spring and operating when moved to release said spring-biased member for outward projection, and means movably carried by said plug body and exposed at the bottom end of said plug body for actuating engagement with said movable control member to effect movement thereof in a direction to release said movable spring-biased member, said plug body having two plug contacts in electrical engagement with two receptacle contact elements and having switching means in electrical connection with said two plug contacts and actuatable in response to actuation of said lastmentioned means.

ll. A signalling plug and receptacle construction comprising a plug body having movably mounted therein a spring-opposed member and having a eXible pull member connected to the latter and extending to the exterior of the plug body whereby said member may be reversibly actuated from a remote point. a receptacle body having a plurality of spring contacts for engagement respectively by such plug contacts as are entered into said receptacle body, said spring contacts being biased inwardly and said receptacle body having therein conductive means with which said inwardly biased contact springs engage whereby plug contacts hold their respectively engaged spring contacts away from said conductive means, springbiased movable means coacting upon movement in a direction opposing its spring-bias to disengage spring contacts from said conductive means and provided with means-operating in response to said movement to hold naeso it against retrograde movement under its spring-bias, and means associated with said spring-opposed member that is carried by said plug body adapted, in response to actuation of said spring-opposed member by said pull member, to coact with said holding means and adapted upon movement to engage and actuate the latter to release said movable means for retrograde movement.

l2. A signalling plug and receptacle construction comprising a plug body, a receptacle body having a recessed end face for entry thereinto of plug contacts of a plug and having contact elements therein engageable by the plug contacts for thereby extending signalling circuits, said receptacle body having a movable spring-biased member projectable out of said end face and said plug body having a hollow space in its bottom end into which a portion of said movable member may enter, means responsive to disengagement of said plug contacts from said receptacle contact elements for eecting closure of at least certain of said signalling circuits and means responsive to inward movement of said movable member from projected position for effecting opening of the signalling circuits that are closed in response to disengagement of the plug contacts from the receptacle contact elements, a movable control member carried by said receptacle body and accessible at its said end face and having means operating to hold said spring-biased member in inward position against the bias of its spring and operating when moved to release said spring-biased member for outward projection, and means movably carried by said plug body and exposed at the bottom end of said plug body for actuating engagement with said movable control member to etect movement thereof in a direction to release said movable spring-biased member, one of said receptacle spring contacts being connected to the common" side of a plurality of signalling circuits of which one circuit has its other side connected to another spring contact and of which the remaining signalling circuits have their rcmaining sides connected to the remaining spring contacts, said plug body having two plug contacts engageable respectively with said common contact spring and said other contact spring with the latter two contact springs thereby held out of engagement with said conductive means, said receptacle having means forming an electrical connection between said common contact spring and said conductive means independently of movement of said common contact spring toward or away from said conductive means, whereby when said means movably carried by the plug body actuates said holding means in releasing direction, said remaining circuits are energized, and switching means associated with said two plug contacts for controlling said other signalling circuit.

13. A signalling plug and receptacle construction comprising a plug body, a receptacle body having a plurality of recesses for the reception of plug contacts, a plurality of receptacle contacts carried by said receptacle body and respectively exposed in said recesses for engagement respectively by such plug contacts as are entered thereinto, one of said receptacle contacts having connected thereto the common side of a plurality of signalling circuits of which the remaining signalling circuits have their remaining sides connected to the remaining receptacle contacts, circuit-controlling means carried by said receptacle body and including conductive means adapted to coact to control at least one of said circuits and having a movable control member therefor with means movably supporting it by said receptacle body, said plug body carrying switching means and having two plug contacts respectively engaging that receptacle contact that is connected to the common side and a receptacle contact in a circuit other than the circuit or circuits controlled by said conductive means, said switching means being connected to said two plug contacts, and control means carried by said plug body for effecting initial conjoint actuation of said control member and said switching means and subsequent actuation of only one of them.

14. A signalling plug and receptacle construction as claimed in claim 13 in which said control means comprises movable means capable of repeated actuation and having means for actuating both said switching means and said control member, and means for holding said control member in actuated position whereby subsequent or repeated actuation of said means effects subsequent or repeated actuation of only said switching means.

l5. A signalling plug and receptacle construction comi l? prising a plug body, a receptacle body having a plurality of recesses for the reception of plug contacts, a plurality of receptacle contacts carried by said receptace body and respectively exposed in said recesses for engagement respectively by suc plug contacts as are entered thereinto, one of said receptacle contacts having connected thereto the common side of a plurality of signalling circuits'of which the remaining signalling circuits havetheir remaining sides connected to the remaining receptacle contacts, circuit-controlling means carried by said receptacle body and including conductive means adapted to coact to control at least one of said circuits and having a movable control member therefor with means movably supporting it by said receptacle body, said plug body carrying switching means and having two plug contacts respectively engaging that receptacle contact that is connected to the` common side and a receptacle contact in a circuit other than the circuit or circuits controlled by said conductive means, said switching means being connected to said two plug contacts and said plug body carrying movable means capable of repeated actuation and having means for actuating both said switching means and control member, means for holding said control member in actuated position whereby subsequent or repeated actuation of said last-mentioned movable means effects subsequent or repeated actuation of only said switching means, a pull member extending from said plug body and having operative connections with said last-mentioned movable 'means whereby the latter may be repeatedly actuated from a point remote from the plug-and-receptacle assembly, and manual means associated with the latter and actuatable from the exterior thereof for releasing said control member from actuated position and thereby condition it for again being actuated in response to actuation of said pull member, said manual means being operable and accessible only at the plug-and-receptacle assembly.

16.. A signalling plug and receptacle construction as claimed in claim 13 in which said switching means comprises a movable switching element within said plug body and spring means biasing it in one direction, said control means comprising a pull member accessible externally of said plug body for manual actuation and connected to said switching element to operate it in opposition to said spring means, and means responsive to actuation of said pull member for actuating said control member.

17. A signalling plug and receptacle construction comprising a plug body, a receptacle body having a plurality of contacts for engagement by plug contact prongs upon assembly of a plug having contact prongs to said recepf tacle body said plug body having a spring-opposed rotary member coaxially carried thereby by means of a hollow cylindrical part, means in said receptacle body responsive to separation therefrom of a plug with contact prongs for closing the circuits of said receptacle contacts and including movable means having an operator exposed to ward said plug body and having holding means with a movable release member therefor, said plug body having a pull member extending therefrom for actuation from a remote point and connected to said spring-opposed rotary' member whereby the latter is responsive to pull of said pull member and said rotary member having means for actuating said release member, and a push member movably carried by said plug body and means operating through said hollow cylindrical part and responsive to push of said push member for operating said operator.

18. A hospital signalling construction comprising a plug body adapted to be assembled to a receptacle construction that has a plurality of contacts with which plug contacts of a plug areinterengageable and in which said receptacle construction is provided with means for closing and opening the circuits of its contacts, said means having a depressible operator disposed toward said plug body for actuating said means in one direction and an operator exposed toward said plug body for actuating said means in the other direction, said plug body having means for securing it to the receptacle construction and carrying two actuating devices for respectively actuating said operators, the actuating device for one of said operators comprising an instrumentality that extends to and is controllable from a point remote from said plug body and the actuating device for the other of said operators comprising'a means externally accessible and controlled only at said plug body.

Cil

19. A hospital signalling construction comprising a plug body adapted to be assembled to a receptacle body having a plurality of contacts for engagement by plug contact prongs upon assembly o a plug having contact prongs to said receptacle body and in which the receptacle body is provided with means for closing and opening the circuits of its contacts with an operator for actuating said means in one direction and an operator for actuating said means in the other direction, said plug body comprising a casing-like structure having means for securing it to the receptacle body and having an aperture therein through which extends a pull member and spring-opposed means carried by said plug body and responsive to pull of said member for actuating one of said operators, and means movably carried by and accessible at said plug body for actuating the other operator.

20. A hospital signalling construction comprising a plug body having two contacts adapted to be assembled to a receptacle construction having a plurality of contacts with two of which said plug contacts are interengageable and in which said receptacle construction is provided with means for closing and opening the circuits of its contacts, said means having a movable operator disposed toward said plug body for actuating said means in circuit-closing direction, said plug body having a movable cam means and an external remotely-controlled element for moving said cam, said cam being engageable withsaid operator to actuate it, a switch in said plug body connected to said two contacts of said plug body, and operative connections between said remotely-controlled element for actuating said switch.

21. A signalling plug and receptacle construction for a plurality of signalling circuits having a common return line comprising a receptacle body having more than two spring contacts one of which is connectible to the common return line whereby said plurality of signalling circuits may be extended when said receptacle spring contacts are engaged by a corresponding number of contacts of a plug assembled to said receptacle body, conductive means carried by said receptacle body and cooperatively related to said spring contacts, said spring contacts being biased toward said conductive means for engagement therewith and being held out of engagement with said conductive means when they are engaged by contacts of a plug assembled to said receptacle body, whereby, upon disassembly of plug contacts from said receptacle body, said spring contacts move toward said conductive means, a plug body having two plug contacts for assembly to said receptacle body with one ot' said plug contacts in engagement with that receptacle spring contact that is connected to the common return line whereby all of the receptacle spring contacts engage said conductive means excepting for the two spring contacts thereof that are respectively engaged by the two plug contacts of said plug body, whereby said two plug contacts extend one of said signalling circuits into said plug body, means forming an electrical connection between said conductive means and said' one spring contact that is connected to the common return line, cam means in said receptacle body for permitting or preventing the other ot said spring contacts to engage said conductive means, means movably carried by said plug body to actuate said cam means to effect and maintain engagement of said spring contacts with said conductive means, and a switch carried by said plug body and connected to said two plug contacts, said plug body having a means movable in reversible strokes for actuating said movable control means on one stroke and for eiecting circuit-closing and circuit-opening switch actuation on its two strokes.

22. A hospital signalling plug and receptacle construction for a plurality of signalling circuits comprising a receptacle having a plurality of contacts therein that are connectible to a plurality of signalling circuits and that are engageable by the plug contact prongs of a plug entered therein upon assembly of the plug to said receptacle and having means responsive to separation therefrom of the plug with its contact prongs for closing the circuits of said receptacle contacts and including control means operable to cause opening and closing of said circuits in the absence of the plug and its contact prongs, and a plug body having contact prong means engageable with such ot' said receptacle contacts as are connectable to one of said plurality of signalling circuits for extending it into the plug body, means responsive to the entry of said 3i i@ prong means upon assembly of the plug body to saidA receptacle for removing said extended signalling circuit from the control of said control means, a switch in said plug body for controlling said extended signalling circuit, said plug body having a remotely controllable springv retracted pull-chainoperated mechanism with the pull chain extendable therefrom to a point remote from the plug body, said mechanism having connection with said switch for reversibly operating'the latter to effect repeated activation of said extended signalling circuit and having a movable actuator element actuated thereby, and means for securing the plug body to the receptacle to resist the pull of the pull chain of said mechanism and for posi tioning the movable actuator element of the plug body relativo to the control means of the receptacle so that the receptacle control means is actuated in circuit-closing direction in response to pull on the pull chain and thereby activate the others of said signalling circuit.

Reliereuees Cited in the file of this patent UNITED STATES PATENTS 

